











é 


N.Y. 


i | v= => “3 Sey BS = Pe higtios : a 1 hates 
= a | on 3 
— 5 a 
eee Fame ws | g 
| Oo | ol 
Ea 
a 
Fmd 





Kodak C 


chester 


oc 





and Filters 








olor Films, 


Color Films, Plates 


and Filters 
for 
Commercial Photography 





Eastman Kodak Company 
Rochester, N. Y. 
1925 


Introduction 


VERY photographer who photographs colored objects 
should know how to make negatives that will faith- 
fully record the monochrome values of the colors. 

Whether the subject is in one color against a background 
of another color or whether it contains two or more colors, 
he should be able to determine, from an examination of 
the subject, whether it is necessary to use color sensitive 
materials and whether an orthochromatic filter should be 
employed or a panchromatic film with either an ortho- 
chromatic or a contrast filter. 

Photographs that faithfully produce»in monochrome, the 
relative brightness of the colors of the subject are an 
absolute necessity for catalogue and book illustrations and 
for use byssalesmen who cannot earry sans of the objects 
the photographs represent. ~ * | 

The making of such photographs is a comparatively 
simple matter when once the principles involved are under- 
stood and in this booklet we undertake to make these prin- 
ciples clear. 

Should any question arise in connection with the subject, 
that we have not answered in these pages, we will be glad 
to deal with it by correspondence. 


EASTMAN KODAK COMPANY, 
ROcHESTER, N. Y. 


December, 1925 


Photographing Colors 


ROM the earliest days of photography it has been rec- 

ognized that the effect obtained when colored objects are 
photographed is different from the effect which the objects 
produce upon the eye. This knowledge, indeed, has spread 
to the general public to the extent that it is common to 
hear dress colors described as ‘‘difficult to photograph,”’ 
while in general the satisfactory reproduction of colored 
objects for catalogue illustration and- other commercial 
purposes has been a most serious problem for the technical 
photographer. 

What the commercial and technical photographer requires 
is a means by which he can reproduce, in monochrome, any 
colors in any relative brightness which he may desire, 
and this can be obtained only by using films or plates that 
are sensitive to all colors, in connection with a series of 
color filters suitable for the whole range of colors likely to 
be met with in practical work. For this purpose, we manu- 
facture Eastman Panchromatic Films and the Wratten Pan- 
chromatic Plate, these being used with the Wratten Filters. 
These panchromatic materials are distinguished by the 
fact that they are completely sensitive to all colors. Or- 
dinary films and plates are sensitive to blue, violet; and 
ultra-violet. Those which are known as ‘‘orthochromatic,’’ 
in addition to being sensitive to these colors, are sensitive 
also to the yellow-green, and since this is the chief com- 
ponent of yellows, they are generally said to be sensitive 
to green and yellow. Panchromatic materials, however, 
are sensitive not only to the blue, violet, green and yellow, 
but also to orange and red, so that they are sensitive to all 
colors which the eye can see. 

Suppose that a photographer wishes to photograph labels 
printed in red, green and blue (see p. 15). Then an or- 
dinary film will photograph the blue as light, the green 
and red, dark; by using an orthochromatic film the green 


3 


CoLor FI_tMs, PLATES AND FILTERS 


will photograph light as well as the blue, but only by the 
use of a panchromatic plate can the red be photographed 
as anything but black. It will be realized that red sensitive - 
materials cannot be developed or handled in the ordinary 
darkroom light. A special safelight must be used, or no 
light at all. 

Eastman Commercial Panchromatic Film has nearly 
twice the speed of Eastman Commercial Ortho Film but 
has been specially sensitized to the red as well as to the 
green and yellow. 

The Wratten Panchromatic Plates are made in two 
varieties. The faster plate, of softer quality, is called the 
Wratten Panchromatic, while a slower plate, of greater 
contrast, is termed the Wratten Process Panchromatic, 
this latter plate being intended for use where great contrast is 
required, as in photographing labels, or for the preparation 
of the line and halftone negatives in photo-engraving. 

Therefore these panchromatic materials especially the 
Eastman Commercial Panchromatic Film are fast enough 
for general work even when filters are used. In fact, under 
some conditions the Panchromatic Film is faster than the 
non-color-sensitive materials. Although the Wratten pro- 
cess Panchromatic Plate is somewhat slower its ability to 
build up great density makes it a very useful plate. 


The Need of Light Filters 


By using panchromatic materials we can photograph a 
scene or object so that every color is given its correct 
relative value in monochrome, but in order to do this a 
filter must be placed in front or back of the lens. The 
reason for this is that even panchromatic materials are 
more sensitive than is the eye, to blue and violet light, in 
comparision with green and red light, and the way to pre- 
vent these colors from exercising an undue effect upon the 
plate is to use a colored filter which will sufficiently subdue 
them before they reach the plate. : 


+ 


For COMMERCIAL PHOTOGRAPHY 


This filter must be accurately adjusted to the sensitive 
material. It must be sufficiently dark to stop the correct 
proportion of blue and violet light, and especially it must 
stop all the invisible but very active ultra-violet light, but 
it must not absorb too much blue light or quite all the 
violet light, because otherwise these colors will be repro- 
duced too dark. Three orthochromatic filters, designated 
by the letter “‘K’’, for use with panchromatic films and 
plates, give the photographer complete control over the 
degree of orthochromatic correction desired and these are 
sold by us either singly or in sets. 

The K1 is a pale yellow filter requiring only 50% more 
than the unfiltered exposure. The K1 filter should be used 
where only a slight correction is needed or where the ex- 
posure must be kept down to a minimum. 

The K2 is the most generally useful filter. It increases 
exposure on a panchromatic film or plate about three times, 
and gives excellent color reproduction. It is the most 
suitable filter for general work. Where the equipment is 
limited to only one filter the K2 is the one we recommend. 

The K3 filter gives a fully corrected color reproduction 
and requires about four and one-half times the unscreened 
exposure on panchromatic films and plates. It is not 
recommended for use with other materials. 


The Reproduction of Color Contrasts 


To the eye, objects are distinguished from their sur- 
roundings by contrast which may be of two kinds. It may 
be a tone contrast or a color contrast. Tone contrast can 
always be correctly reproduced photographically, but the 
result of the reproduction of a color contrast will depend 
on the photographic method used. 

Consider, to illustrate, two objects one placed upon the 
other and distinguishable from each other by the eye solely 
upon their color contrast—such as a bright red apple in a 
cluster of green leaves. The color contrast to the eye is 


5 


CoLor FILMS, PLATES AND FILTERS 


marked, although the tone contrast is small, that is, one 
color is really as dark as the other. Photographed with an 
ordinary film or plate both reproduce dark and, instead of 
contrast, a mass of black is recorded. If, now, a pan- 
chromatic material is used, with the K3 filter, both colors 
are reproduced in the same tone values seen by the eye: 
the contrast disappears and the colors are represented by a 
uniform field of gray. ) 

What, then must be done to obtain a satisfactory re- 
production of this color contrast? It is quite clear that 
it is impossible in the case suggested to reproduce the color 
contrast in a photograph so long as tone values are correctly 
recorded, consequently we must sacrifice the correct ren- 
dering of either the red or the green. If a green filter is 
used the green will appear lighter and the red darker; if we 
use a deep orange filter, the red may be lighter, the green 
darker; and which shall be used must be governed by cir- 
cumstances. If we over-correct the color contrast, it is 
usually better to over-correct towards the red (making 
a bright red, lighter) since red, as a rule, seems to us more 
brilliant than green. 

Again, with perfect orthochromatism, a yellow straw- 
stack against a blue sky may give a result, in which the 
strawstack cannot be distinguished from the sky. Here 
again it would perhaps be better to over-correct, though 
the individual must decide for himself in each case whether 
color contrasts shall be partly corrected, fully corrected, or 
over-corrected. 

The procedure we have been describing enables us to 
indicate color contrast, though it is a departure from true 
orthochromatism. 


For COMMERCIAL PHOTOGRAPHY 
Color Contrasts for Special Purposes 


There is another case of the photography of color con- 
trast, which is to the commercial workers of as great, if 
not greater, importance and that is the photographing of 
colored objects to secure the best possible general results 
for advertising purposes. 

If it is desired to photograph a colored object as black, 
it must be photographed through a filter that will completely 
absorb the color of the subject. No rays of light reflected 
from it will then reach the plate and, as a consequence, it 
will be reproduced as though it were black. For example, 
consider the label shown on p. 15. If a red filter is used 
the blue and green will be absorbed and will photograph 
more or less dark, while the red is transmitted and photo- 
graphs so well that the white word “negative” is indis- 
tinguishable. 

If no filter is used, or if a green filter is used, the red 
will appear black and the black lettering consequently 
lost. In order, therefore, to properly show all the colors, 
together with the black and white lettering, it is necessary 
to use the K3 filter which gives a correct reproduction. But 
the examples with the red filter and without a filter show 
how certain contrasts could be obtained if necessary. 

The most important application of this method occurs in 
the photography of furniture, where the results are indeed 
gratifying. If a piece of polished red mahogany furniture is 
photographed on an ordinary film or plate, no trace of 
grain is usually visible. To this plate, both the red and 
yellow portions of the wood are black; to give increased 
exposure simply results in the appearance of a plentiful 
crop of ordinarily invisible scratches in the photograph. If, 
however, Eastman Panchromatic Films or Wratten and 
Wainwright Panchromatic Plates, are used with the “A’”’ 
(orange-red) filter, the results are entirely different; the 
scratches disappear and the grain of the wood comes up in 


i 


CoLor Fi_Ms, PLATES AND FILTERS 


the most wonderful way. In fact, so great is the difference 
that it may seem incredible, to those who have never used 
panchromatic materials. 

In all furniture-photography success depends chiefly upon 
the selection of the filter for the particular subject to be 
photographed. Where mahogany is to be photographed, 
in most cases the greatest contrast can be obtained by the 
use of the “‘A”’ filter, the orange-red color of this filter giving 
the strongest contrast between the lighter and darker 
portions of the wood, thus rendering the grain in the most 
striking way. It must be remembered when photographing 
furniture for the purpose of catalogue illustration, that the 
object of the manufacturer is to make the article appear as 
attractive as possible, and to do this the natural grain of 
the wood must be shown in the illustration. The furniture 
can be photographed before being varnished and rubbed, 
when the results, if not quite so accurate, are attained with 
much less exposure. The same technique is used. 


With yellow woods, such as oak, satinwood, and walnut 
a red filter is of little advantage, and the “‘G’”’ contrast 
filter, which is of a strong yellow color, will be found suffi- 
ciently deep. 

When photographing inlaid furniture, too much exaggera- 
tion must be avoided, and when we have inlaid mahogany 
of the Sheraton type, it is somewhat difficult to render in 
its full strength the red grain of the mahogany without 
at the same time showing yellow inlays too white. The 
matter must be compromised and the “A”, “G” or “K3” 
filter used, according to the particular subject and the effect 
required (See p. 16). The effect of the filter can generally be 
judged by simply looking at the subject through the filter to 
be used. 

For the most difficult cases of very dark, old mahogany 
or rosewood, it is sometimes necessary to use the ‘“F” 
(deep red) filter, but this must be regarded as a reserve 
power, only to be used when absolutely necessary, because 


8 


For COMMERCIAL PHOTOGRAPHY 


the manner in which it over-corrects all lighter tones is 
liable to give a general impression of exaggeration to the 
resulting photographs. 

Tapestries and carpets are usually photographed with a 
“K3” filter, but if they contain much yellow, red and also 
light blues, the results will be found to be too flat, and for 
such work the ‘‘A’’ filter is more suitable. If a green carpet, 
with a red design, is to be photographed, and it is desired 
to clearly pick out the red design from the general light 
green ground, the green ‘‘B’”’ filter will be found most 
suitable. But where an important piece of work is under- 
taken, it is generally advisable to try one negative with a 
“K2” or “K3”’ filter in order to get an orthochromatic 
rendering before using a contrast filter, as it is desirable to 
avoid over-correction unless the subject necessitates it. 

Subjects for which a correct orthochromatic rendering 
is particularly desirable are reproductions of posters, labels 
and other forms of advertising matter in colors. Posters, 
for instance, in which the figures of persons are outlined 
against a bright yellow ground, if reproduced upon an 
ordinary film or plate, will convince anyone that there are 
subjects for which the ordinary non-color-sensitive material 
may not prove all that can be desired. In copying maps, 
a ‘‘K3”’ filter must be used if the map contains several 
colors, but in those which more often come to the com- 
mercial photographer, such as real estate maps, a contrast 
filter is frequently required to accentuate some special 
color in the original. For photographing new houses, and 
indeed most architectural subjects, the ‘‘G’”’ filter with an 
Eastman Panchromatic Film will give admirable results, 
avoiding the full tone in which red bricks are too often 
reproduced, especially in dull or hazy weather. 

Sometimes it is necessary to copy a print which has be- 
come yellowed with age. As ordinary films or plates are 
sensitive only to the blue, violet and ultra-violet rays, 
which are more or less absorbed by this yellow paper, 


9 


CoLor FILMs, PLATES AND FILTERS 


if a negative is to be made of such a print, the yellow paper 
will appear dark or gray. If a color sensitive material is 
used, with a yellow contrast filter, the yellow stain will 
have no effect and will fail to photograph. It should be 
noted that the yellow filter to be used for such a purpose 
should not be an orthochromatic filter, if the best results 
are required, but one which is much stronger, such as the 
Wratten “G’’ filter. An orthochromatic filter is made 
to photograph objects in their tone values, as seen by the 
eye, and if the yellow stain is visible to the eye, it will also 
photograph through the orthochromatic yellow filter. If 
the yellowed print be examined through the strong ‘‘G” 
filter, the yellow stain of the paper will not be visible. 
Sometimes however a better result may be obtained with an 
ordinary plate—it depends upon the nature of the print. 
The illustrations on page 18 show photographs of a 
print which had been splashed with a yellow dye, leaving 
a conspicuous stain. In the first photograph, made on an 
ordinary film, the stain appears quite black, while in the 
second one, for which an Eastman Panchromatic Film and 
the ‘‘G”’ filter were used, the stain has disappeared. 
Another difficulty is encountered in copying prints that 
are of a brown color, such as found in Sepia, D.O.P., Carbon 
or re-developed Bromide prints. This brown color has a 
very strong absorption for the violet light, to which the 
plate is sensitive, consequently such prints when photo- 
graphed give negatives having too much contrast or without 
detail in the shadows. It will generally be found that 
increasing the exposure will not satisfactorily reproduce 
such photographs. The obvious course is to photograph 
them as they are seen by the eye; that is, by means of a 
fully correcting (K3) filter and a panchromatic film or plate. 
A difficult task, without the proper plate and filter, is 
the photographing of engineers’ or architects’ blue prints, 
as it is impossible to obtain satisfactory results by using 
the ordinary plate. Nor can orthochromatic films, with 


10 


For COMMERCIAL PHOTOGRAPHY 


yellow filters, give the best results, owing to the fact that a 
great deal of the yellow-green light to which such films are 
sensitive is reflected by the blue print. Therefore, in 
order to obtain really first-class results, the “A” or the 
“F” filter should be used with Wratten Process Panchro- 
matic plates, thus photographing the print by red light, 
which completely absorbs the blue. With such a plate and 
filter, the negatives made from blue-prints are in every way 
as satisfactory as could be obtained from photographing a 
black and white print in the ordinary way. 

The photography of purple or violet typewriting can be 
accomplished in the same manner, by the use of the Green 
“B”’ filter and the Wratten Process Panchromatic Plate. 
Not only is the purple typewriting reproduced, but any 
corrections in red will also be shown as black, while if a 
red filter is used red ink will disappear. 

The commercial photographer often receives orders for 
prints that are to be colored by hand—to show the colors 
of the subject. In such cases his work will be much easier 
if the negative is made with a ‘‘K3”’ filter on a panchro- 
matic film. It is impossible to make either a colored print 
or a colored lantern slide correctly reproducing a subject 
containing yellows and reds from an ordinary negative. 
The ordinary plate shows these colors too dark, but the 
panchromatic film used with the “‘K3”’ filter will faithfully 
photograph all colors in correct relationship to each other, 
and a print from such a negative can be colored so that 
the colors will accurately reproduce the colors of the subject. 

We can put this whole matter briefly in another way by 
saying that white light is a combination of all the colors 
of the spectrum. Objects appear colored because they 
absorb all the colors of the spectrum except their own, 
which they reflect, so that a 

Red object absorbs blue and green light; a 

Green object absorbs blue and red light; a 

Deep Blue object absorbs green and red light; a 


11 


CoLor FILMs, PLATES AND FILTERS 


Yellow object absorbs blue light; a 

Magenta or Purple object absorbs green light; a 

Light Blue or Blue Green object absorbs red light. 

If a colored object is looked at or photographed through 
a filter of a color which it absorbs, it appears or photographs 
dark, so that with a blue filter red, green and yellow ob- 
jects all photograph dark and blue, light; blue-prints photo- 
graph like black-and-white prints through a red filter; 
typewriting (purple) through a green filter, and so on. 

If a colored object is looked at or photographed through 
a filter of its own color it appears light and any markings 
appear well defined. Golden oak shows its grain best 
through a yellow filter, red polished mahogany through a 
red filter. 


Films and Plates 


From the point of view of color-sensitiveness there are 
three kinds of sensitive materials: 

(1) Ordinary materials, such as Eastman Commercial 
Films, give the same monochrome rendering of colored 
objects that we see when we look through the deep blue 
(“‘C’’) filter. They are sensitive only to blue and violet 
light and are but little affected by green or red light. 

(2) “Ortho” materials, such as Commercial Ortho Films, 
when used without any filter, give almost the same rendering 
of colors as ordinary materials except that they are more 
sensitive to yellow. But when used with a yellow filter 
they reproduce yellows and greens quite well, so the various 
colors are recorded in nearly the monochrome values we 
see when looking through the green (‘‘B’’) filter. 

(3) Panchromatic films and plates are sensitive to all 
colors, but when used without any filter, blues photograph 
too bright. To get tones rendered correctly a ‘‘K3’’ filter 
must be used and this will suitably record all colors in 
monochrome. Only panchromatic materials can be used 
with Red or Orange filters. 


12 


FoR COMMERCIAL PHOTOGRAPHY 


List of Wratten Contrast Filters 


The set of light filters for general commercial work con- 
sists of eight filters, ‘‘K1,”’ ‘‘K2”’ and ‘“K3”’ being ortho- 
chromatic filters, and ‘‘G’’ a deep yellow filter for contrast 
work; “A,” “‘B,” “C”’ being the standard tri-color set and 
“F” a deep red filter for special work. 

The orthochromatic material referred to is Eastman 
Commercial Ortho Film. 

“Multiplying factor’ is the number the exposure without 
any filter, must be multiplied by to give correct exposure. 
These figures are only intended as rough indications of 
the increase in exposure which the use of the filter will 
entail; the exact factors for the filters vary with each batch 
of emulsion and are shown on a card enclosed in each box. 


Approximate Multiply- 
ing Factors 
For Eastman 


Panchromatic 
NAME USE Films and For 
Wratten Pan- Ortho- 
chromatic chromatic 
Plates Materi 


“K1” Very Light As a correcting filter when short 
Yellow exposure is of greater impor- 
tance than full correction. 1% 3 


“K2” Light Yellow For general work with Ortho 
plates and films. The best 
single filter for panchromatic 
materials, 3 6 


“K3”’ Yellow To obtain full correction with 
panchromatic films and plates. 44 12 


“G” Strong Yellow To obtain detail in subjects 

where the contrasts are in 

yellow color—such as oak 

furniture. 6 30 
“A” Orange Red Used only with panchromatic 

materials. To obtain contrast 

and detail in subjects of yel- 

low and brown—such as ma- 


hogany furniture. 12 
*“‘B” Green For photographing typewritten 

letters and rendering greens 

light and reds dark. 10 12 
“C’’ Deep Blue To photograph blue as white; 

greens, yellows and reds dark. 10 5 
“F” Deep Red To photograph blue-prints and 

reproduce reds light. 24 


Us 


CoLor FILMs, PLATES AND FILTERS 


Kinds of Filters 


Wratten Light Filters are supplied in two forms—the 
gelatin film filters, which are not protected by glass, and 
the glass filters, in which the gelatin filters are cemented be- 
tween pieces of optical glass. Gelatin film filters are. used 
mostly for experimental work. For regular work they are not 
recommended, as the film is easily marked by the fingers 
and the filters are apt to deteriorate on prolonged exposure 
to the atmosphere. Gelatin film filters may be fitted be- 
tween the lenses or held in a cardboard frame that can be 
fitted over the lens mount. 

It is best, however, for regular work to use filters that are 
cemented in glass. Glass filters are made circular to be 
fitted in slip-on cells and also square of any size desired. 

Filters in ‘“‘B”’ glass, two inches, three inches, and four 
inches square, can be used in our Adjustable Filter Holders. 

The two-inch filter holders are for use on lens mounts 
measuring from one and one-eighth to one and nine-six- 
teenths inches outside diameter. The three-inch filter holders 
are for use on lens mounts from one and eleven-sixteenths 
to two and three-eighths inches diameter, and the four-inch 
on lens mounts from two and three-eighths to three and 
seven-eighths inches outside diameter. 

The adjustable Filter Holders will be found especially 
desirable by all who use several filters, or several lenses on 
which filters are to be fitted. The filters can be inserted 
and removed instantly. 

We carry a full assortment of all ordinary sizes of filters 
mounted in slip-on cells. For this form of fitting it is neces- 
sary to send us the outside measurement of the lens barrel, 
and this measurement must be made very exactly. If a 
pair of sliding calipers cannot be obtained a strip of hard 
writing paper should be wrapped around the lens so that 
the ends over-lap and then the two pieces of paper, where 
they just over-lap, should be cut through, while in position, 
with a sharp knife. 


14 


PHOTOGRAPHS OF A LABEL 


EASTMAN 
yh NU iW 


iti 
niet 





Facsimile of Original 


PANCHROMATI 
FILM 


FOR MOTION PICTURES. 





Commercial Film Commercial Panchromatic 
Without Filter Film and Red “ A”’ Filter 





Commercial Panchromatic 
Film and “K3” Filter 


15 


PHOTOGRAPHS OF FURNITURE 





Facsimile of Original 


Eastman Panchromatic Film 
with “K3” Filter 


16 


PHOTOGRAPHS OF A ROSE 





Facsimile of Original Commercial Film 





Eastman Panchromatic Film Eastman Panchromatic Film 
with “G” Filter with “A” Filter 
17 


PHOTOGRAPHS OF VELOX PRINT WITH YELLOW STAIN 





Commercial Panchromatic Film with ‘‘G”’ Filter 


18 


For COMMERCIAL PHOTOGRAPHY 


Quality of Glass Filters 


Wratten Filters are supplied cemented in two qualities 
of glass plates, ‘“‘A’”’ glass and ‘‘B”’ glass. 

Wratten Filters cemented in ‘‘A”’ glass are known as 
Flats. ““A”’ glass is ground with the same accuracy as the 
best anastigmat lenses, and the completed filters are about 
one-half inch thick. 

Flats are recommended whenever long focus lenses are 
used, for three-color process work, where successive ex- 
posures must be made without changing the focus of the 
lens; in telephotography, and also in all cases when the very 
best obtainable results are desired. | 

“B” glass is selected from the best quality of optical 
plate glass. Wratten filters in ‘‘B”’ glass are most exten- 
sively used and are suitable for all ordinary commercial 
and landscape photography. We do not carry holders for 
“A” glass filters in stock, but make them to order. 


Developing Panchromatic 
| Films and Plates 
Darkroom Methods 


There is no doubt that the greatest obstacle to the use 
of red sensitive materials is the belief that it is difficult to 
develop them. This belief is chiefly due to the conservatism 
which instinctively shrinks from any change in the methods 
to which photographers are accustomed, but we actually 
find that most people who have accustomed themselves 
to the use of panchromatic materials experience no difficulty 
whatever, and even prefer the new methods to those which 
they formerly used. 

There are two methods of developing panchromatic films 
or plates; they may be developed in a developing tank or 
covered tray, using the safelight merely for seeing dishes, 


19 


CoLor FILMS, PLATES AND FILTERS 


etc.; or they may be developed in an uncovered tray a 
few feet from a Wratten Series 3 Green Safelight. For either 
method it is convenient to obtain one of the Wratten Series 3 
Green Safelights. These safelights are made on the follow- 
ing principle: 

The eye is sensitive to all colors if the light is sufficiently 
bright, but as the intensity of light becomes less, the eye 
becomes less sensitive to red; and proportionately more 
sensitive to green; when the green light is very faint, it 
will be much brighter to the eye than any other light 
by which it is safe to develop. 

When developing a film or plate sensitive to all colors, 
we must use the light by which we can see the most with 
the least possible tllumination, and this condition is realized 
by the green safelight. These safelights are made of a sheet 
of glass coated with a bright yellow gelatin film and another 
sheet coated with a bright green film, bound face to face 
with a thick sheet of green paper between, the colors being 
spectroscopically correct. 


Wratten Safelights 


The various kinds of Wratten Safelights are made with 
scientific precision. The colors must be, and are, exactly 
adjusted by us in the spectroscope and by trial with the 
plates. But it should be remembered that no light is really 
“‘safe’”’ if the sensitive plate is exposed to it long enough. 
The standard we have adopted is an exposure of the dry, 
sensitive material, for which the safelight is designed, for 
4% minute, 3 feet distant from the lamp, the illuminant 
being a 10-watt lamp if used in the Eastman or Brownie 
Safelight lamps, and 25-watt if used with the Kodak, or 
Wratten Safelight lamps. The material is less sensitive 
when wet. Exposure to the safelight in excess of this 
amount should not be given if fog is to be avoided, but 
more exposure may be given if the illuminant is weaker. 

When you first turn out the white light in a darkroom 


20 


FoR COMMERCIAL PHOTOGRAPHY 


where there is a green safelight, you will scarcely see the 
light itself, but if you wait a few minutes, most objects 
near the light will become plain, and at the end of fifteen 
minutes you will probably have doubts as to the safety 
of the light, which has become quite bright. These safe- 
lights are 3/16 of an inch thick and can be made in any 
size. If the safelight gets very hot, the film will crack off 
the glass, so that lamps for safelights must be well ven- 
tilated. We have designed a special lamp, the Wratten 
Safelight Lamp, which transmits only reflected light and is 
properly ventilated. It is described on page 31. Darkroom 
lamps fitted with ordinary safelights are not safe for these 
emulsions and red light must be absolutely avoided. 


Developing 


An instruction card is placed in every box. This card 
is printed in our factory, after actual tests of each batch of 
films or plates have been made in the laboratory. The card 
gives the particulars for tray and tank development, the 
time for both being given at temperatures of 50°, 65°, and 
80° F., without danger of frilling. For temperatures in be- 
tween those given, develop for an intermediate length of time. 

The time of development necessarily varies for different 
batches. The correct time of development for both the 
tank and tray methods is stated on the instruction card 
packed in every box. This time is suitable for negatives 
that will print well on Vitava paper, but may be modified 
to give stronger or weaker negatives to suit the individual 
workers by increasing or decreasing the time of develop- 
ment, using our figures simply as a guide. 

If tray development is to be used, have your developer 
ready and a large cover that will completely cover the 
tray, permitting no light whatever to enter. Pour on the 
developer and immediately cover the tray, rocking it gently 
during the time of development. If a green safelight is not 
used, it is necessary to work in absolute darkness. 


Zt 


CoLor Fi_tmMs, PLATES AND FILTERS 


For ordinary contrasts, using Eastman Commercial Pan- 
chromatic Films or Wratten Panchromatic plates, Formula 
D-1 developer is recommended. 


Pyro-Soda Developer 


Formula D-1 

Avoirdupois 

Sodium Bisulphite or Potassium Mee er ey. 
Pein : : . ok eas 
Potassium Bromide... .°.... . =. nr ers. 
Water, to make... es wy Sa 

B Water a ye a a ae 
Sodium Sulphite (E. KC. ) PME 

C Water, : 2 ig ee 
Sodium Carbonate (E. K Co: hs MEE ae en 


For use dilute as follows: 
Tank Development— 
Take 514 ounces each, A, B and C and add water to make one gallon. 
Tray Development— 
Take 1 part of A, 1 part of B, 1 part of C, and 7 parts of water. 


For developing Process Panchromatic films and plates Formula 
D-11 is recommended. 


Elon-Hydroquinone Contrast Developer 
Formula D-11 


Hot water (about: 125° F.) 2°. 3. 4. 
Elon 0. 2. a Se 
Sodium Sulphite (E. K. Co.) ~% . | 2) 
Hydroquinone . toe vw a Sy Rae ee a 
Sodium Carbonate (E. K. Co.) . 4 oo 34 02. 
Potassium Bromide. . 2a a Ee 
Cold watertomake . . . Mr 


Use full strength at 65°. For ee contrast, dilute with an equal volume 
of water. 


22 


For COMMERCIAL PHOTOGRAPHY 
Fixing 


If you use the following acid fixing bath the light can 
be turned up after fixing has proceeded for three minutes. 


Acid Fixing Bath (Formula F-1) 


Hypo RIE Sea al ed oe ee Ee ees 4416 ..0Z8; 

Water , le 64c0zs. 
Dissolve, and add the following hardening solution: 

Water Ce Mere 18 ee Ow ae Pelky  anee ide eyrae 

Sodium Sulphite (E. K.Co. w a, oa Tht aos Cae ees Os 

Acetic Acid (28% ure). Po iiy yk at FT) 9? eye hy os toad Sen OLS 

Potassium Alum : MR Metra to SMe 2 tLe tee ae ee SOF. 


If you prefer ‘io or alkaline hypo, no exposure must 
be made to the light until fixation is complete. Always 
use fresh, strong and clean fixing baths. Old and discolored 
ones are sure to produce trouble. With the Wratten double 
coated plates thorough fixing is important, and the plates 
must not be removed from the fixing bath until it is certain 
that they are completely fixed. 

To make up the hardener, dissolve the chemicals in 
water at about Ioo degrees Fahrenheit in the order 
given above. The sodium sulphite should be completely 
dissolved before adding the acetic acid, after the sul- 
phite-acid solution has been thoroughly mixed add the 
potassium alum. Pour the hardener solution slowly 
into the cold hypo solution while stirring the hypo 
solution rapidly. The hypo should be thoroughly dis- 
solved before adding the hardener, otherwise a pre- 
cipitate of sulphur is likely to form. 

For those who prefer a chrome alum formula, the 
following is suggested: 


Chrome Alum Fixing Bath for Films and Plates 
(Formula F-16) 


Pe wOm ee Not ee hon ol i ae ee 2b, 
Prema ouiniite (bs Kh. Co.) wn. Od ar fa 2 ZB. 
Water to make 96 ozs. 


Zo 


Cotor Fitms, PLATES AND FILTERS 


Bo Water oes ite OE rl ee eee 
Potassium Chrome Alum . . °. . ..°. 9 2.025 
Sulphuric Acid—pure conc, . >... 4, 9) ee 


Pour B solution into A solution slowly while stirring A 
rapidly. This formula is especially recommended for 
use in hot weather, but it loses its hardening properties 
in a few days either with or without use, and therefore 
should be used as soon as possible after mixing. This 
formula, when fresh, hardens the film more thoroughly 
than the potassium alum formula, and is, therefore, to 
be preferred in hot weather, but it should be renewed 
frequently. Formula F-1 gives satisfactory hardening 
throughout its active life and as an all around bath is 
to be preferred. 


Hardening Baths 


In hot weather the following hardening bath should 
be used after development and before fixation in con- 
junction with Formula F-1, or when the bath F-16 
does not harden sufficiently. 

Chrome Alum Hardening Bath for Films and Plates 

(Formula SB-3) 


Water: 0005 © 2 a 
Potassium Chrome Alum . . eh es 1 oz. 


After development rinse the films or plates for one 
or two seconds and place for two or three minutes in 
the above bath. Agitate the films for several seconds on 
first immersing in the hardening bath, otherwise a 
chromium scum will tend to form on the film, which is 
very difficult to remove. Then place in the fixing bath. 
Trouble from stains, blisters and airbells is largely 
prevented if the film or plates are agitated on first 
immersing in the fixing bath, and at intervals until 
fixation is completed. 

This hardening bath 1s a blue-violet color by artifical 
light, when freshly mixed, but it ultimately turns yellow- 


24 


For CoMMERCIAL PHOTOGRAPHY 


ish-green with use. It then ceases to harden and should 
be replaced with a fresh bath. A freshly mixed and 
unused bath will keep indefinitely, but the hardening 
properties of a partially used bath fall off rapidly on 
standing for a few days. 

It is very important to observe the precautions re- 
garding agitation of the film on first immersing in the 
hardening bath in order to prevent the formation of 
chromium scum. The scum is produced by the action 
between the chrome alum and the alkaline developer 
carried over on the film, but it does not form if the bath 
is acid. If the film is not agitated the hardener solution 
in immediate contact with the film becomes alkaline 
and it precipitates a chromium hydroxide tends to 
form. Agitation of the film will prevent this. When the 
bath becomes old, a scum will tend to form even when 
the films are agitated. The bath should then be dis- 
carded. 

These films should always be washed with water and 
wiped with cotton after washing in order to remove any 
possible traces of scum because once the film is dry it 
is impossible to remove it. 

For full particulars for handling film under hot 
weather conditions, see the booklet on “Tropical 
Development.” 


The Importance of Rinsing 


When a film is transferred from the developer to the 
fixing bath, the alkali in the developer retained by the 
film neutralizes some of the acid in the fixing bath. 
When a certain quantity of acid has been destroyed in 
this way, the fixing bath precipitates white sludge, 
rendering it useless. The addition of developer also 
gradually destroys the hardening properties of the fixing 
bath. Therefore, by removing as much developer as 


25 


Cotor Fitms, PLATES AND FILTERS 


possible from the film by thoroughly rinsing in water, 
the life of the fixing bath is much prolonged, while the 
tendency for stains and blisters to form is very much 
reduced. 

In warm weather it is only possible to rinse for one 
or two seconds, otherwise the film will soften. If the 
chrome alum hardening bath above is used, rinsing in 
water may be omitted, although a previous rinse for a 
few seconds in water, will prolong the life of this bath 
also. 


The Life of a Fixing Bath 


A fixing bath is exhausted either when a sludge forms 
or when the fixing power of the hypo is reduced to such 
an extent that there is danger of some silver remaining 
in the film after fixing for the normal time. Sludging 
can be prevented by a thorough rinsing after develop- 
ment. 

The F-1 and F-16 baths above will completely fix 
the equivalent of 75—8 x Io inch films or plates per 
gallon of solution provided a thorough rinsing water 
precedes fixation. If the acid hardening bath is used, 
the fixing bath will not precipitate a sludge as readily, 
and the equivalent of 1oo—8 x Io inch films or plates 
may be fixed per gallon. 


Halation 


By the use of film halation is avoided. In order to prevent 
halation with the Wratten Panchromatic and Process Pan- 
chromatic Plates they are now made double coated. 


26 


For CoMMERCIAL PHOTOGRAPHY 


Technical Books on the 
Photography of Colors 


The Photography of Colored Objects, 102 pages, bound in board, 


(new edition) 


Wratten Light Filters, 82 pages (for scientific workers) 


Photomicrography, 44 pages 


Prices of Eastman Commercial 


Panchromatic Film 


Prices Include Excise Tax 


Size Per Doz. 
314x444 ye 
344x5% 1.03 
eS 1.03 
447x6% 1.50 
434x6% P55 
cs pio ae | 1.65 
eS ae 1.96 
614x8% 2.53 
mel 3.14 
be xii *3..66 
se x 10 3.66 
10 x 12 ‘ 6.39 
Fa ed ; 6.39 
11 x 14 : 9.18 
Sx 20 é 9.48 
12 x 20 nA oS 
14 x 17 Et See 
16 x 20 . 20.8 

30 x 60 


Size 


17 x 20 
13 30:22 
20 x 24 
20 x 26 
22 x 24 
20 x 28 
yw ae 
22 x 28 
20 x 30 
22 x 30 
24 x 30 
25 x 30 
24 x 36 
24 x 40 
28 x 36 
30 x 34 
26 x 40 
30 x 40 


.pil7. 


Eastman Commercial and 
Commercial Ortho Film 


Prices Include Excise Tax 


ize Per Doz. 
3x44 .67 
3Y4x5% .93 
A eS .93 
4x6 1.34 
434x6% 1.39 

ae | 1.50 
Ay 8 1.75 
614x844 Dect 
7: ox £0 2.84 
(Meee Ba gi 3.30 
ie om Y LS eat (4 


27 


37 


1s 


CoLor Fitms, PLATES AND FILTERS 


Prices Include Excise Tax 


Size Per Doz. Size Per Doz. 
At ee «aie oe taba Dem gh oh i 24% 36... \ aes 
ZO OO A SARS ent ae 24x40. . 94°) eee 
De De ke Pe ee Le Oe 25 x 30... ee ee ee 
DONS l Mace, Ce eee aed say eae) 26 x40. « ieee 
DL nO Po ak eens yee eee 28 x36: 4. ee 
pe we os] | Wileemebeaibe 20g oe 39.12 30 x 34) 5) 5 ee 
24, 8°30 0 tae 42.68 30 x 40 5 ee eae 

" 30 x 60. . $106. 70 


The 5x7, 64x8% and 8x 10 sizes are put up in 2 dozen packages 
at $2.99, $4. 54 and $6.60 respectively. 


Nai epee sizes of Eastman Film will be furnished at approximately proportion- 
ate prices to the next larger size. 

When furnished in quantities of less than regularly listed packages, the price will be 
figured per sheet, at proportionately the rate per dozen sheet package, plus additional 
charge for packing, about 10 per cent. 


Prices of Wratten Panchromatic and 
Process Panchromatic Plates Double Coated 


Prices Include Excise Tax 


Size Per Doz. Size Per Doz. 
SRA ee Bae ee eee 10 x 12.4 fee Bhs wes 
BigKh a oe Wa eee Vote: 1.14 tl x 1473 | eo 10.40 
eS 1g 144x17):.. 2. eee 
44x64 tevt 12x20 “6 ) 30 (re 

, ats 1.86 16x20 ©. ° ¥ eee 
6144x8% 2.85 18 x22. oie See 

x 10 4.14 20x 24° . - 5 ee 
I fo ee | 4.14 


Wratten Filters 


Unmounted 
Gelatin Film Cemented in ‘‘B”’ Glass Circles or 
Unmounted Mounted in Squares in 
Inch Circles Squares Metal Cells A Glass 
34 S20) St.15 Ysa 15 $2. 40 ae 
1 .20 1.30 1.30 7.55 6.50 
1% .20 eee nae 2 SY eee 
1% .20 1.45 1.45 2.85 9.00 
15; .20 ie fas 3.153 =e 
13% .20 1.65 oe 3.15> 3 
1% 25 1.65 1.65 3.35 11528 
Zs aks Cte ieee 3.30 tees eee 
1% .30 E75 3.303 ae 
14 .30 ae Wick 345 ee eee 
134 .30 1.90 1.90 3.45... $2 ere 
1% 35 2.10 a 4.90) 3. 4 eae 
14 635 amit te: ae 4,20. <a 
2 .40 2710 2.10 4.20 12.75 
2% 45 2.25 2°25 4.50. aa eee 


28 


For COMMERCIAL PHOTOGRAPHY 
Wratten Filters (Continued) 


Unmounted 

Gelatin Film Cemented in ‘‘B’’ Glass Circles or 

Unmounted Mounted in Squares in 

Inch Circles Squares Metal Cells A Glass 
2% Yate) Tee 2,85 O° GUS Oe none 
245 tapes ga eae C00 Me ares 
23% .60 Bio, 2535 Gt C0 Gary ee ees 
2% 65 2585 2.85 6.00 18.00 
25% 70 note eee 1200s at Ue Goce 
234 .80 Lee S75 (Teh ae ie cA 
3 .90 SAS Ses) 7.50 Zon oU 
314 25 ee Gans PSOE. FE ee 
31% 1225 5.65 S505 tae ace ae 31.50 
4 1.60 Gus 5 6.75 13.50 39.00 
44 1.70 9 Ais Sade sce 45.00 
5 1.70 G40 0 gees 60.00 


Specify i in your order ehether Film Filter or Filter Cemented in ‘‘B”’ 
Glass is desired. 

Note: Where no prices are quoted on Cemented Filters, ‘‘B’’ Glass, Circulars or 
Squares, Unmounted, in the schedule above, the cost will be figured at an increase of 
50% over the next larger listed size. 

Note: When ordering ‘‘B”’ glass filters for use in mounts already purchased give the 
exact diameter of the filter required. This i is necesary because the size varies according 
to the diameter of the cell in which it is to be used. 


Standard Sets of Filters 3 Inches Square 
Commercial set of 8—A, B, C, F, G, K1, K2, and K3. 


Price per set, case included. In ‘‘A’’ Glass ee) Se. 5k 2042.00 
Price per set, case included. In ‘‘B”’ Glass : a Ge 35.00 
Gelatin Film “ites hi ieee ar oe ee 1220 


Commercial set of 3— K3, G ane A. Specially suitable 
for photographing oak and mahogany furniture. 


Price, per set, case included. In ‘‘A’’ Glass ger) Li) 2 a ee OSU 

Price, per set, case included. In ‘‘'B’’ Glass ia are 16.50 

Gelatin Film only . aos ay ets 2.70 
Sets of A, B, and ae ae Color F DESER ones 

Price, per set, case included. In ‘‘A’’ Glass el Fe 8 oe ALO 50 

Price, per set, case included. In ‘‘B’’ Glass __.. Sie 78 16.50 

Gelatin Film only . ae; : ger 20 


We make upwards of 100 Rete filters es if a filter 
is required for a special purpose we can probably supply 
it. Condensed Price List of Filters sent on request. 


er. Filter Holders 


For 2-inch Square Filters. Will fit lens mounts 1 6 to 1 1 inch 
diameter. ... $1.25 


29 


CoLor Fitms, PLATES AND FILTERS 
For 3-inch Square Filters. Will fit lens mounts 1 to 23% inch 


diameter. . $1.50 
For 4-inch Square. Filters. Will fit lens mounts 2 ie ‘inch to 
3%inch diameter . . 2:50 


Filter Test chee 


Consists of 12 small viewing filters, mounted in cardboard, for 
examining the subject to determine which filter should be used. 
Eastman Filter Test Chart. : ...: ©). 2 9) Se 


Wratten Safelights 


These safelights consist of one or two sheets of glass 
coated with a colored gelatin film, which transmits a 
perfectly safe light in which to handle the sensitive material 
for which they are recommended. 

Series 00. Yellow light for use with D. O. P. papers, such 
as Vitava, etc. 

Sertes 1. An orange safelight te use with ordinary, 
medium and extra rapid films or plates which are not 
color sensitive. Consists of yellow and orange coated glass, 
with red paper between. 

Series 2. A safelight for extra rapid and orthochromatic 
films or plates, which are sensitive to green but not to red. 
This safelight consists of yellow and violet-colored glass 
with deep red paper between. 

Series 3. This is the green safelight for use with the red- 
sensitive panchromatic material. It gives a faint illumina- 
tion, which grows quite strong as the eyes become accus- 
tomed to it. This safelight consists of yellow and green 
coated glass with green paper between. 

Sertes 4. Bright green safelight for use with ordinary 
films or plates, for those who are unable to use a red light. 
Not safe for orthochromatic materials. 


PRICE WRATTEN SAFELIGHT. (Any Series) 


ie a7 Ph SoS Bie Oe $1.25 10 x 1232 Gyetees 
2% dia. and 3 4 x 434 (for Brownie Safelight Lamp) per pair . 65 


Special sizes supplied at an advance of 3314% above 
the price of next larger size from which they can be cut. 


30 


For COMMERCIAL PHOTOGRAPHY 
Wratten Safelight Lamp 


The Wratten Safelight Lamp is radically 
different in construction from the ordinary 
darkroom lamp in that none but reflected 
light is permitted to pass. This is accom- 
plished by building the lamp practically 
twice the height of the ordinary lamp. 

The electric bulb is placed inside the 

lamp at the top. By means of a white 

os heii enameled curved reflector the rays of light 

Lamp from the lamp aboveare evenly diffused over 

the surface of the safelight which is fitted to the lower por- 
tion of the lamp front. 

The safelight glass is eight by ten inches, affording 
ample illumination for the inspection of large films or plates. 

The Wratten Safelight Lamp is constructed for use with 
electric light only, and includes electric 
lamp attachment with six feet of cord and 
plug and one safelight. 


WRATTEN SAFELIGHT LAMPS ARE MADE 
IN Two STYLEs: 

No. 1 is fitted with a safelight, and also 
with a sheet of opal glass. The opal glass 
furnishes white light illumination. It is 
covered with a light-tight slide when safe- ogee Wratten 
: : : ae é f afelight 
light illumination only is desired. Lamp 

No. 2 is fitted with safelight only. 

In ordering, specify which series of safelight is desired. If 
not specified, Series 2 will be furnished. 

The Kodak Safelight Lamp is similar in principle to the 
No. 2 Wratten lamp but is smaller. 

The Eastman Safelight Lamp carries a 5 x 7 safelight 
and has a screw plug fitting any droplight or wall socket. 
A useful lamp where shelf space is limited. 

The Brownie Safelight Lamp screws into an electric 


31 








CoLor FILMs, PLATES AND FILTERS 


light socket and is little larger than the electric bulb it 
holds. Very desirable when working in close quarters. 


THE PRICE 
(Including one Wratten Safelight of any Series.) 
Wratten Safelight Lamp No.1,8x10 . . . $10.00 
Wratten Safelight Lamp No. 2, 8 x 10 ee 8.00 
Kodak Safelight.Lamp, 5x 7 . = 93) 3.50 
Eastman Safelight Lamp, 5 x 7 ; fecie: 3.00 


Brownie Safelight Lamp, Circular an p V4 dia. 
and side size 3% x 434, Safelights, any series 
included . bi oN ON 82 175 


All prices are subject to change without notice 
EASTMAN KODAK COMPANY, 
RocHESTER, N. Y. 


32 





643 South Hill S 


St. 





